Question 1

What is conversion efficiency for 110v to 220v upconvert?  2400 watt is already right at the limit for a house 110v 20 amp circuit breaker!

Accepted Answer

The issue here - as with most of the questions I am seeing - is the amperage on the 110V circuit.  2400W amounts to over 20AMPS on the house circuit. Most US house circuits are not rated
at even 20AMPS (this is why US kettles take so long to boil water by comparison with European kettles).  Use at full rated power for short periods is OK but I would strongly advise running
long periods at full rated power - especially if the house has older wiring - unless you know the circuit is wired for 20 AMPS.

Question 2

If the input voltage is 220v/50hz, will it be able to produce 110v/60hz?

Accepted Answer

No, we have another item 220V to 110V step down voltage converter to produce 110V, you could check on Amazon.

Question 3

Can it transform frequency from 60hz to 50hz in US? or transform voltage  only ?Can i use it for 220v 50hz tube amplifier?

Accepted Answer

All most all converters in this price range do NOT convert the frequency, i.e. USA 60 Hz to EURO 50 Hz. However, for many electronic devices such as TVs, monitors, (radios, computers, etc., and for "non-inductive" loads (lamps, small heaters, etc)  these converters work fine.  For "Inductive" loads - things which have transformers or motors such as sewing machines, fans, motorized small kitchen appliances - the devices may buzz and / or fail prematurely because the wire windings in the transformer or motor were designed to work with 50Hz not 60Hz.  In the specific case of a tube amplifier, it depends on the amplifier's power supply - most of these have transformers - so it might act as mentioned.  Usually wrong frequencies into a transformer will cause them to produce more heat than normal - make sure you supplie ample cooling, e.g. add a fan. (Electrical Engineer here)

Question 4

is this device like a power bank or do you have to have it plugged in while using it

Accepted Answer

yes, you need.to plugged in while using it. is not a power bank.  in china is 220v  in U.S 110v  i need that input 110v and output 220v

ASIN	B071FCWQ5T
Best Sellers Rank	#103,480 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #388 in Power Converters
Brand	UMI
Brand Name	UMI
Current Rating	10 A
Customer Reviews	4.5 out of 5 stars 402 Reviews
Item Highlight	Electric Transformer 120v to 240v Voltage,Asia Use in US Canada Mexico,Heavy Duty Power,Auto Mode,Safe CE Certified,White
Item Weight	18.7 pounds
Manufacturer	UMI
Maximum Frequency	60 hertz
Minimum Frequency	60 hertz
Model	LX-2400
Mounting Type	Wall Mount
Number of Items	1
Part Number	LX-2400
Power Source	Corded Electric
Specification Met	CE, CQC
Warranty Description	2 Year Manufacturer

UMI 2400W Step Up Voltage Converter, 110v to 220v Power Transformer

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